import React, { Component } from 'react'

export default class Son extends Component {
  state = {
    num:888
  }
  render() {
    const { num } = this.state
    const { fn } = this.props
    return (
      <div>
        <h4>
            Son -- {num} 
        </h4> 
        <button onClick={() => {
          fn(num)
        }}>
          调用
          </button>
      </div>
    )
  }
}
